Skeletal system, bone cells and ECM

Question 1

Why is the bone classed as an organ?

Answer 1

It’s a collection of tissues that together perform a function.

Tissues include: bone, cartilage, blood

Question 2

Name the six broad functions of the skeletal system and their function.

Answer 2

[SPAM B is FAT]

1. Support - structure for the body
2. Protection for internal organs
3. Assistance in movement - muscles attach to the skeleton
4. Mineral homeostasis - major calcium and phosphorous reservoir
5. Blood cell production - produce white and red blood cells
6. Triglyceride storage - energy reserve

Question 3

Describe the general structure of bone tissue (and ECM) and the 3 components of ECM

Answer 3

Abundant ECM (extracellular matrix) surrounded by widely separated cells

ECM = water, collagen, crystallised mineral salts

Question 4

What’s an osteoprogenitor?

Answer 4

An unspecialised bone stem cell

Undergoes cell division to become oestoblast

Question 5

What’s an osteoblast?

Answer 5

Immature bone cells surrounded by ECM; become osteocytes

Bone formation, initiate calcification

Secrete ECM

Question 6

What’s an osteocyte?

Answer 6

Mature bone cell

Question 7

Osteoclast

Answer 7

Break down ECM

Regulate calcium in blood